ISO 20602:2019
(Main)Ships and marine technology — Check valves for use in low temperature applications — Design and testing requirements
Ships and marine technology — Check valves for use in low temperature applications — Design and testing requirements
This document specifies requirements of design, manufacture, and test methods for cryogenic check valves to have excellent quality of leakage stability in very low temperature environments (−50 °C to −196 °C).
Navires et technologie maritime — Clapets de retenue destinés aux applications à basse température — Exigences de conception et d'essai
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INTERNATIONAL ISO
STANDARD 20602
First edition
2019-05
Ships and marine technology — Check
valves for use in low temperature
applications — Design and testing
requirements
Navires et technologie maritime — Clapets de retenue destinés aux
applications à basse température — Exigences de conception et d'essai
Reference number
ISO 20602:2019(E)
©
ISO 2019
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ISO 20602:2019(E)
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© ISO 2019
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Published in Switzerland
ii © ISO 2019 – All rights reserved
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ISO 20602:2019(E)
Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Pressure temperature rating . 3
4.1 Types of fluids . 3
4.2 Working pressure and designed temperature . 3
5 Design . 3
5.1 General structure of a check valve . 3
5.2 Materials — General . 3
5.3 Body . 4
5.3.1 Materials . 4
5.3.2 Manufacturing . 4
5.4 Cover (bonnet) . 5
5.4.1 Types . 5
5.4.2 Materials . 5
5.5 Disc . 5
5.5.1 Types . 5
5.5.2 Materials . 5
5.6 Gasket . 5
5.7 Valve Seat . 5
5.7.1 Types . 5
5.7.2 Materials . 6
5.8 Hinges and hinge pin (as applicable). 6
5.8.1 Types . 6
5.8.2 Materials . 6
5.9 Bolts and nuts . 6
5.9.1 Types . 6
5.9.2 Materials . 6
6 Surface treatment . 6
7 Welding and heat treatment . 6
7.1 Welding . 6
7.2 Heat treatment . 6
8 Test and inspection . 6
8.1 Material test . 7
8.2 Non-destructive inspection . 7
8.2.1 Radiographic testing (RT) . 7
8.2.2 Penetrant testing (PT) . 7
8.2.3 Ultrasonic testing (UT) . 8
8.2.4 Retest . 8
8.2.5 Reporting test result . 8
8.3 Dimension check . 8
8.4 Visual inspection . 8
8.5 Heat treatment inspection . 8
8.6 Pressure tests . 8
8.7 Fire safety test . 9
8.8 Cryogenic tests . 9
8.8.1 Test scope . 9
8.8.2 Test procedure . 9
8.8.3 Submission of test result .10
9 Marking .11
© ISO 2019 – All rights reserved iii
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ISO 20602:2019(E)
Annex A (informative) Cryogenic check valves — Examples .12
iv © ISO 2019 – All rights reserved
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ISO 20602:2019(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
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on the ISO list of patent declarations received (see www .iso .org/patents).
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URL: www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 8, Ships and marine technology,
Subcommittee SC 3, Piping and machinery.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
© ISO 2019 – All rights reserved v
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INTERNATIONAL STANDARD ISO 20602:2019(E)
Ships and marine technology — Check valves for use
in low temperature applications — Design and testing
requirements
1 Scope
This document specifies requirements of design, manufacture, and test methods for cryogenic check
valves to have excellent quality of leakage stability in very low temperature environments (−50 °C to
−196 °C).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 5209, General purpose industrial valves — Marking
ISO 28921-1, Industrial valves — Isolating valves for low-temperature applications — Part 1: Design,
manufacturing and production testing
API 594, Check Valves: Flanged, Lug, Wafer, and Butt-welding
API 598:2016, Valve Inspection and Testing
API 6FA, Specification for Fire Test for Valves
ASME B16.5, Pipe Flanges and Flanged Fittings
ASME B16.10, Face-to-Face and End-to-End Dimensions of Valves
ASME B16.25, Buttwelding Ends
ASME B16.34:2017, Valves-Flanged, Threaded, and Welding End
ASME BPVC Sec. V, Nondestructive Examination
ASME BPVC Sec. VIII, Div.1:2018,Pressure Vessels
ASTM A182, Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged
Fittings, and Valves and Parts for High-Temperature Service
ASTM A194, Standard Specification for Carbon Steel, Alloy Steel, and Stainless Steel Nuts for Bolts for High
Pressure or High Temperature Service, or Both
ASTM A320, Standard Specification for Alloy-Steel and Stainless Steel Bolting for Low-Temperature Service
ASTM A351/A351M, Standard Specification for Castings, Austenitic, for Pressure-Containing Parts
ASTM E186/280/446, Standard Reference Radiographs for Heavy-Walled Steel Castings
BS 1868, Specification for steel check valves (flanged and butt-welding ends) for the petroleum,
petrochemical and allied industries
BS 6364, Specification for valves for cryogenic service
© ISO 2019 – All rights reserved 1
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ISO 20602:2019(E)
MSS SP-55, Quality Standard for Steel Castings for Valves, Flanges and Fittings and Other Piping Components
- Visual Method for Evaluation of Surface Irregularities
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http: //www .electropedia .org/
— ISO Online browsing platform: available at http: //www .iso .org/obp
3.1
nominal diameter
DN
alphanumeric designation of size for components of a pipework system, used for reference purposes
which comprises the letters DN followed by a dimensionless whole number that is related to the physical
size, in millimetres, of the bore or outside diameter of the end connections
Note 1 to entry: The number following the letters DN does not represent a measured value and shall not be used
for calculation purposes except where specified in the relevant standard.
Note 2 to entry: In those standards that use the DN designation system, any relationship between DN and
component dimensions shall be given, e.g. DN/OD or DN/ID.
[SOURCE: ISO 18139:2017, 3.1]
3.2
nominal pressure
PN
numerical designation relating to pressure that is a convenient round number for reference purposes
Note 1 to entry: It is intended that all equipment of the same nominal size (DN) designated by the same PN
number shall have the same mating dimensions appropriate to the type of end connections.
Note 2 to entry: The permissible working pressure depends upon materials, design and working temperature
and has to be selected from the pressure/temperature rating tables in corresponding standards.
[SOURCE: ISO 18139:2017, 3.2]
3.3
nominal pipe size
NPS
dimensionless number for the purpose of pipe, flange, or flanged fitting end connection size
identification
Note 1 to entry: The number is not necessarily the same as the flange or flanged fitting inside diameter.
[SOURCE: ISO 18139:2017, 3.3]
3.4
class
alphanumeric designation used for reference purposes related to a combination of mechanical and
dimensional characteristics of a component of a pipework system, which comprises the word “class”
followed by a dimensionless whole number
[SOURCE: ISO 18139:2017, 3.4]
2 © ISO 2019 – All rights reserved
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ISO 20602:2019(E)
4 Pressure temperature rating
4.1 Types of fluids
The types of fluids are shown in Table 1.
Table 1 — Types of fluids
Temperature
Type Liquid density (density)
(in atmospheric pressure)
LNG
3
−163 °C to −88 °C (434 kg to 478 kg/m )
(Liquefied natural gas)
NG
3
−160 °C to −65 °C (0,7 kg to 0,89 kg/ m )
(Natural gas)
LN2
3
−196 °C (804 kg/m )
(Liquefied
...
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